diff --git a/homeassistant/components/netatmo/sensor.py b/homeassistant/components/netatmo/sensor.py
index be7e0f3e971..327d9ecc52f 100644
--- a/homeassistant/components/netatmo/sensor.py
+++ b/homeassistant/components/netatmo/sensor.py
@@ -223,7 +223,7 @@ class NetatmoSensor(Entity):
     @property
     def available(self):
         """Return True if entity is available."""
-        return bool(self._state)
+        return self._state is not None
 
     def update(self):
         """Get the latest data from Netatmo API and updates the states."""